Fabrication of Nano-Aluminum Nanoparticles Thin Films by Vacuum Coating and Study on its Surface Plasmon Resonance Properties

Aluminum nanoparticles(AlNPs) thin films were fabricated by DC magnetron sputtering coating.Two methods were used to obtain localized surface plasmon resonance(LSPR) of AlNPs. One is the deposition of nano-aluminum on a quartz substrate at room temperature followed by annealing under vacuum at elevated temperatures, and the other is the deposition of nano-aluminum on a hot quartz substrate. The morphology, crystal structure,composition and absorption characteristics of the samples were characterized by transmission electron microscopy,scanning electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectroscopy. The effects of substrate temperature and deposition time on the LSPRs of the nano-aluminum prepared by the two methods were studied by comparison. It was found that the former is ineffective while the latter is effective. The position and intensity of the LSPR can be tuned by adjusting the deposition time of Al thin films. Furthermore, due to the selflimited oxidation of AlNPs, the LSPR of AlNPs of average thicknesses larger than 3 nm was mainly determined by the agglomeration degree of the AlNPs. This study promotes the understanding of the LSPR properties of AlNPs and their applications.